1) Field of the Invention
The present invention relates to a packet processing system separated from or integrated with a forwarding device and a control device. More specifically, the present invention relates to a packet processing system which enables a control device to dynamically set a packet transfer rule between the control device and a forwarding device even if a new application is started on the control device and which can thereby separate and integrate the forwarding device and the control device without modifying a conventionally used application.
2) Description of the Related Art
Recently, as the development of the Internet progresses, networks have become large in size and accelerated and service requirements have diversified. Accordingly, demand for a control processing ability of a communication device that constitutes each network and for information processing resources such as a necessary memory is rapidly increasing. In these circumstances, many trial have been taken to separate the communication device into a forwarding device and a control device, to provide the control device that satisfies the rapidly increasing demand for the information processing resources, and integrate the network.
For example, P1520 Reference Model [Gilad Goren] (doc), Documents, Foils and Minutes of the Fifth WG Meeting, held in Princeton (Jan. 18 to 19, 1999), which was obtained on http://www.ieee-pin.org/ by Internet search on Apr. 16, 2003, discloses a first conventional art which has been studied by the IEEE P1520WG for definitions of forwarding device and a control device and prescriptions of an interface (hereinafter, “IF”) between them regarding to a communication device that constitutes a network in order to provide an integrated network. Serial forum, “Master of IP Network”, Hajime KAMITANI, Toru IMANO, which was obtained on http://www.atmarkit.co.ip/fnetwork/rensai/index/index-serial.html#1b/ by Internet search on Mar. 20, 2003, discloses a second conventional art for distributing a service request to an appropriate control device based on a packet transfer protocol between a preset forwarding device and a control device if the forwarding device receives the service request to a virtual control device on the forwarding device from a network node.
However, the first conventional art has the following disadvantage. In the first conventional art, with a view of providing the integrated network, the definition of the forwarding function and the control function and the prescription of the IF between them regarding to the communication device that constitutes the network are considered. Nevertheless, the disadvantage which arises to the network and which arises when the forwarder function and the control function of the communication device that constitutes the network are separated is not overcome yet.
For example, according to the second conventional art, if the forwarding device receives the service request to the virtual control device on the forwarding device from the network node, the service request can be distributed to an optimum control device based on the preset packet transfer protocol between the forwarding device and the control device. However, if a new application is started on the control device, the packet transfer rule between the control device and the forwarding device cannot be dynamically set. As a result, it is disadvantageously necessary to modify the conventionally used application or manually set the packet transfer rule.